1. Field of the Invention
The present invention relates to an air suspension system for a vehicle, and more particularly to an air suspension system for a vehicle designed to allow air to circulate in a closed circuit between an air tank and a spring.
2. Description of the Related Art
FIG. 1 is a circuit diagram of a conventional air suspension system for a vehicle.
The conventional air suspension system for the vehicle serves to allow air in an air tank 2 to be supplied to an air spring 6, or to allow air to be withdrawn from the air spring 6 to the air tank 2 by means of a compressor 4 via several valve means 10 provided among the air tank 2, the compressor 4, and the air spring 6, respectively. Furthermore, the air suspension system allows outside air to be added to the air tank 2 or allows air in the air tank 2 to be discharged to the outside via the valve 10.
Meanwhile, an air drier 12 to dry air is equipped in a line through which outside air is introduced or discharged, and a pressure sensor 14 to measure the pressure of the air tank 2 or of the air spring 6 is equipped in a line through which air circulates between the air tank 2 and the air spring 6.
However, in the conventional air suspension system for the vehicle disclosed above, the air tank 2 and the air spring 6 are not connected to each other by means of an in-line structure, and the line through which air flows is complicatedly entangled. As a result, there occur problems of a large air pressure loss and of low responsiveness.
Additionally, the conventional air suspension system has the air drier 12 exposed to the outside, so that even when air is not added to the air tank 2, outside air is always introduced into the air drier 12. As a result, there occur problems in that the air drier 12 has a large volume, and in that the air drier 12 is excessively operated, causing ineffective operation of the air drier 12.